The present article addresses some theoretical considerations on ecolinguistics on a meso- and micro-scale and then illustrates them through some elements taken from two sets of observations made in multilingual schools in highly multilingual settings, one in Europe (Luxembourg) and the other one in the South Pacific (New Caledonia). Both case studies show the variety of possibilities in the management of classroom ecologies. According to the specific environments, there are very different ways to foster the communication and the development of pupils and younger children, depending also on their autonomy and their access to empowerment in the educational process. Multilingual strategies at school can be situated on a continuous scale from more implicit to more explicit policies and they have to be considered in relationship to other social structures with importance for education like the family or the workplace or leisure time occupations.